EP4154628A1

EP4154628A1 - System and method for selecting, using a terminal, an optimum frequency band in terms of speed

Info

Publication number: EP4154628A1
Application number: EP21725209.7A
Authority: EP
Inventors: Regis GUINVARC'H; Israel HINOSTROZA; Sylvain AZARIAN
Original assignee: Office National dEtudes et de Recherches Aerospatiales ONERA; CentraleSupelec
Current assignee: Office National dEtudes et de Recherches Aerospatiales ONERA; CentraleSupelec
Priority date: 2020-05-20
Filing date: 2021-05-17
Publication date: 2023-03-29
Also published as: FR3110803B1; FR3110803A1; WO2021233843A1

Abstract

An aspect of the invention relates to a method for automatically selecting, using a terminal (300), an optimum frequency band in terms of speed from a group of frequency bands, comprising the following steps: - selecting, using the terminal (300), an initial frequency band from the group of frequency bands and measuring an initial speed which is considered to be the reference speed; - applying a plurality of combinations of attenuations, comprising at least one attenuation of the gain of an antenna system (200) which is connected to the terminal (300) over a frequency band of the group of frequency bands: - for each combination of attenuations, measuring a speed and, if the measured speed is greater than the reference speed, selecting the measured speed as the reference speed; - if the reference speed is greater than the initial speed, applying the combination of attenuations corresponding to the reference speed.

Description

DESCRIPTION

TITLE: System and method allowing the selection by a terminal of an optimum frequency band in terms of throughput

TECHNICAL FIELD OF THE INVENTION The technical field of the invention is that of communication networks and in particular that of the selection by a terminal, of a frequency band on which to establish a communication within a network. Communication.

The present invention relates to a method allowing the automatic selection by a terminal of an optimum frequency band in terms of throughput from among a set of frequency bands selected by the terminal. The present invention also relates to a system for implementing such a method. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] In order to be able to exchange data within a communication network such as a mobile telephone network, a user via his terminal establishes a communication with a base station. Communication can be established on a set of frequency bands defined according to the type of network: for example for 4G in France, communication can be established on five frequency bands, the frequency band B28, the frequency band B20 , the frequency band B3, the frequency band B1 and the frequency band B7.

[0004] Conventionally, the terminal automatically selects one of the possible frequency bands as a function of rules supplied to it by the base station and of the radio reception conditions on these frequency bands. These rules have been established by the standards and can be configured by the operator of the communication network in order to distribute the available frequency bands as efficiently as possible between the numerous users of the communication network. [0005] The selection of the frequency band by the terminal is therefore partly governed by considerations of internal management of the communication network and not exclusively by considerations of optimum performance for the user. Thus, it is not uncommon for the upward flow on the frequency band selected is less than the uplink rate that the terminal could have if it had selected another frequency band.

[0006] There is therefore an interest for a terminal in being able to select a frequency band having an optimal throughput without having to modify the operation of the current communication networks and that of the terminal.

SUMMARY OF THE INVENTION

The invention offers a solution to the problems mentioned above, by allowing a terminal to automatically select an optimum frequency band in terms of throughput from among a set of frequency bands selectable by the terminal without modifying it, without modifying its operation. and without modifying the rules and the management parameters of the communication network.

A first aspect of the invention relates to a method allowing the automatic selection by a terminal, of an optimum frequency band in terms of throughput from among a set of frequency bands selectable by the terminal to establish a communication with a base station , the set of frequency bands belonging to a maximum set of known frequency bands, the terminal being connected to an external intelligent antenna system comprising at least one antenna, an attenuation module and a system board, the method comprising, after reception by the terminal of at least one message from the base station comprising a plurality of rules and parameters to be applied by the terminal to select a frequency band from among the set of frequency bands, the following steps: - Selection by the terminal, d 'an initial frequency band among the set of frequency bands by application of the plurality of rules and parameters es;

Measurement of an initial upward flow and an initial downward flow by the system board via the terminal on the initial frequency band; - Choice of the initial uplink rate as the reference uplink rate and the initial downlink rate as the reference downlink rate;

Application by the attenuation module of at least one sequence of combinations of attenuations to the antenna, each combination of attenuations comprising at least one attenuation of the gain of the antenna on a given frequency band of the maximum set of frequency bands: o For each combination of attenuations applied, measurement of an upward flow by the system board via the terminal:

• If the measured uplink debit is strictly greater than an uplink debit threshold depending on the reference uplink debit, choice of the measured uplink debit as the reference uplink debit;

If the reference uplink flow is greater than the initial uplink flow, application to the antenna, of the combination of attenuations corresponding to the reference uplink flow by the attenuation module: o Measurement of a downstream flow by the system board via the terminal :

• If the measured downward flow is greater than or equal to a downward flow threshold depending on the reference downward flow, the combination of attenuations applied corresponds to the optimum frequency band in terms of flow.

[0009] Thanks to the invention, frequency bands are artificially attenuated to reduce the quality level of the signal received on these frequency bands. The terminal, which therefore no longer manages to communicate correctly on these frequency bands, is then forced to select, with the selection rules and the parameters which have been allocated to it, a frequency band which is not or less attenuated.

The sequence of combinations of attenuations therefore makes it possible to define a set of frequency bands that the terminal can select as a function of the selection rules and parameters, the set of frequency bands therefore depending both on the sequence of combinations of 'attenuations, selection rules and parameters and the radio environment to which the terminal is exposed. The set of frequency bands is a priori unknown and belongs to or is equal to a maximum set of known frequency bands comprising all the frequency bands likely to be used depending on the location and / or the type of communication network in which is located. find the terminal. By measuring an upward flow for each of the frequency bands selectable by virtue of the sequence of combinations of attenuations, that is to say for each of the frequency bands among the set of frequency bands, it is then possible determining the frequency band exhibiting an optimal uplink rate and causing the terminal to select and remain on this frequency band by applying the corresponding combination of attenuations to it. A downward flow measurement is then performed on the frequency band to verify that the downward flow is at least equal to the initial downward flow. Indeed, the downstream flow measurement is the most time consuming flow measurement and in terms of data and this is the reason why the downward flow measurement is only checked once at the end to minimize the duration of the process. [0012] Thus, the invention allows a user to benefit from an optimal uplink speed, and can for example significantly improve the Very High Speed Radio solutions alternatives to xDSL or DOCSYS access points, in particular in the case where the access point is too far from its dispatcher and encounters recurring outage and speed problems.

[0013] In addition to the characteristics which have just been mentioned in the previous paragraph, the method according to the first aspect of the invention may have one or more additional characteristics among the following, considered individually or in any technically possible combination.

According to a first embodiment, if the set of frequency bands comprises N frequency bands, the sequence of combinations of attenuations comprises N combinations of attenuations, each combination of attenuations comprises N-1 attenuations applied to the bands frequencies of the maximum set of different frequency bands.

Thus, each combination of attenuations is directly associated with a given frequency band of the maximum set of frequency bands and the set of frequency bands is equal to the maximum set of frequency bands. According to a second embodiment, each combination of attenuations comprises at most two attenuations applied to frequency bands of the maximum set of different frequency bands.

Thus, the method according to the invention can be implemented by an intelligent antenna system according to the invention comprising a certain type of attenuation modules which can attenuate only on two frequency bands simultaneously in order to have a size allowing the intelligent antenna system to maintain sufficient positive gain.

The gain of the antenna system being equal to the sum of the gain of its antenna, greater than 6 dB in a preferred embodiment, and the insertion losses of its attenuator, that is to say the loss of signal power due to the connection between the antenna system and the terminal, less than 2 dB in a preferred embodiment, the term “sufficient positive gain” is understood to mean a gain equal to a minimum of 4 dB over all the frequencies.

[0019] According to a first variant embodiment compatible with the first and the second embodiment, the method according to the invention further comprises a step of identifying the optimum frequency band in terms of throughput. [0020] According to a second variant embodiment compatible with the first and the second embodiment and with the first variant embodiment, the method according to the invention is associated with at least one circumstantial item of information. [0021] Thus, it is possible to associate the optimal upward flow and the downward flow associated with circumstantial information, such as the time or the location of the flow measurement.

According to a sub-variant embodiment of the first and of the second variant embodiments, the method according to the invention comprises a step of storing the optimum frequency band in terms of throughput identified in a database, the band optimal frequency in terms of throughput being associated with the circumstantial information in the database.

[0023] Thus, it is possible to know for a given circumstantial information item, the optimum frequency band (s) in terms of bit rate most likely to accelerate the method according to the invention. According to an alternative embodiment of the previous sub-variant embodiment, the sequence of combinations of attenuations depends on the associated circumstantial information or on the optimal frequency band (s) in terms rate corresponding to the associated circumstantial information in the database.

[0025] Thus, the sequence of attenuation combinations can be modified to accelerate the process by favoring the optimal frequency band (s) in terms of the most probable bit rate.

According to an alternative embodiment compatible with the previous embodiments, for the initial frequency band and for each combination of attenuations applied, the upward and / or downward flow rate is measured after a predefined time interval. Thus, the terminal is stabilized on the frequency band selected at the time of measurement.

According to an alternative embodiment compatible with the previous embodiments and alternatives, the method according to the invention is carried out as soon as a repetition condition is met, the condition depending on a clock, on a change of detectable environment or a significant flow variation from an expected flow.

Thus, the process is repeated periodically, at certain times, or when the flow measurement is significantly altered compared to the expected flow.

According to an alternative embodiment compatible with the previous embodiments and alternatives, the method according to the invention comprises a step of forcing a selection by the terminal, of a frequency band from among the set of frequency bands, after each application of a combination of attenuations.

Thus, the forcing step is carried out in the case where the selection by the terminal of a frequency band from among the set of frequency bands is not carried out automatically after a change in the radio conditions created by a combination of 'attenuations applied. According to a sub-alternative embodiment of the previous alternative embodiment, the method according to the invention comprises a step of stopping the application of the combination of attenuations applied after each forcing step.

[0033] Thus, the combination of attenuations is not maintained once the terminal has selected the corresponding frequency band.

A second aspect of the invention relates to a system for implementing the method according to the invention, comprising: a terminal comprising at least one antenna port configured to allow connection between an intelligent antenna system and the terminal; an intelligent antenna system comprising: o an antenna; o a mitigation module comprising:

• a programmable attenuator configured to apply a sequence of attenuation combinations to the antenna, each attenuation combination including at least one antenna gain attenuation over a given frequency band;

• a controller configured to program the attenuator; o a system board configured to drive the controller and perform uplink and downlink flow measurements via the terminal when the system is connected to the terminal via the antenna port.

According to an alternative embodiment, the attenuator comprises at least one strand notch filter and at least one PIN diode, the controller being configured to activate or deactivate the PIN diode to increase or decrease the electrical length of the strand of the wire. stranded notch filter.

Thus, it is possible to program the attenuator by modifying the resonant frequency of the stranded notch filter and therefore the attenuation frequency by the stranded notch filter, by modifying the size of the strand via the '' activation / deactivation of the PIN diode functioning as a switch. Such an attenuator is characterized by low insertion losses, less than 2 dB.

[0037] According to an alternative embodiment of the previous alternative embodiment, the attenuator comprises a plurality of stranded notch filters in series.

[0038] Thus, it is possible to attenuate simultaneously on two frequency bands. Such an attenuator is of a size allowing the intelligent antenna system to have sufficient positive gain.

According to an alternative embodiment compatible with the previous alternative embodiment, the antenna comprises: a broadband spiral antenna element; a power supply configured to power the antenna element via a coaxial cable; a cavity comprising the antenna element and a through hole; with the coaxial cable configured to pass through the hole so that the power supply is outside the cavity.

[0040] Thus, the antenna is broadband, it covers in particular all the high frequency frequency bands used for 4G or 5G, and flat and has a reduced manufacturing cost. In addition, it has a positive gain greater than 6 dB.

[0041] According to an alternative embodiment of the previous alternative embodiment, the power supply comprises an infinite balun.

[0042] Thus, the power supply is carried out coplanar with the antenna, which makes it possible to improve the compactness of the antenna system.

The invention and its various applications will be better understood on reading the following description and on examining the accompanying figures.

BRIEF DESCRIPTION OF THE FIGURES

The figures are presented as an indication and in no way limit the invention. FIG. 1 is a block diagram illustrating the sequence of the steps of the method according to the invention.

Figure 2 shows a schematic representation of the system according to the invention connected to a terminal communicating with a base station. - Figure 3 is a schematic representation of a first embodiment of the antenna element of the system according to the invention.

Figure 4 is a schematic representation of a first embodiment of the attenuator of the system according to the invention.

FIG. 5 is a schematic representation of a sequence of combinations of attenuations according to a second embodiment of the method according to the invention.

Figure 6 is a block diagram illustrating the step of identifying the optimal throughput frequency band associated with the sequence of attenuation combinations shown in Figure 5.

DETAILED DESCRIPTION

Unless otherwise specified, the same element appearing in different figures has a single reference. A first aspect of the invention relates to a method allowing the automatic selection, by a terminal, of a frequency band of optimum flow, among a set of frequency bands, in order to establish a communication with a base station at the same time. within a communication network. [0047] [Fig. 2] Figure 2 shows a schematic representation of the terminal

300 communicating with the base station 400 within the communication network. The terminal 300 is for example a mobile phone, such as a smartphone, a computer, a 4G router or even a tablet. In FIG. 2, the terminal 300 is a 4G router. The terminal 300 comprises at least one antenna port 301 configured to allow a connection between the antenna system of the terminal 300 and an intelligent antenna system 200 external to the terminal, as illustrated in FIG. 2. The terminal 300 comprises a radio modem and fixed or wireless connection sharing means for connecting to the Internet in order to carry out measurements of uplink rates and downlink rates. In the context of the invention, it is assumed that the terminal 300 is fixed.

The communication network is for example a mobile telephone network, such as for example a GSM network (for "Global System for Mobile Communications" or 2G, a UMTS network (for "Universal Mobile Telecommunications System") or 3G, or another LTE (for “Long-Term Evolution”) or 4G / 5G network.

The method is carried out after reception by the terminal 300, of at least one message from the base station 400 comprising a plurality of rules and parameters to be applied by the terminal 300 to select a frequency band from among a maximum set of known frequency bands.

The message is for example received when the terminal 300 is turned on.

The maximum set of frequency bands groups together the different frequency bands that can be used by the terminal 300 depending on the location and / or the type of the communication network.

For example, in France, only six frequency bands with an uplink are used for mobile networks: - the frequency band B28 corresponding to 703-748 MHz in uplink and 758-803 MHz in downlink ; the frequency band B20 corresponding to 832-862 MHz uplink and 791-821 MHz downlink; the frequency band B8 corresponding to 880-915 MHz uplink and 925-960 MHz downlink; the frequency band B3 corresponding to 1710-1785 MHz uplink and 1805-1880 MHz downlink; the frequency band B1 corresponding to 1920-1980 MHz in uplink and 2110-2170 MHz in downlink; the frequency band B7 corresponding to 2500-2570 MHz in uplink and 2620-2690 MHz in downlink.

The maximum set of frequency bands therefore includes in France the frequency bands B28, B20, B8, B3, B1 and B7. The frequency bands B28, B20 and B8 are referred to as low frequency bands and the frequency bands B3, B1, B7 as high frequency bands. The term "low frequency frequency band" means a frequency band comprising frequencies below 1000 MHz and the term "high frequency frequency band" means a frequency band comprising frequencies above 1000 MHz.

For example, on a 4G network in France, communication can be established on five frequency bands, B28, B20, B3, B1 and B7. The maximum set of frequency bands therefore includes the frequency bands B28, B20, B3, B1 and B7.

In practice, the frequency bands B28 and B20 cannot be used simultaneously in 4G and the maximum set of frequency bands therefore includes the frequency bands B20, B3, B1 and B7 or B28, B3, B1 and B7. In general, in France, for the most frequently deployed types of communication networks, the maximum set of frequency bands available for a terminal on a given type of network comprises at most four frequency bands, and more particularly at most one low frequency band and at most three high frequency bands.

[0063] In the prior art, the terminal 300 is forced to select a frequency band from among the maximum set of frequency bands by applying the selection rules and parameters received. The selected frequency band is therefore exclusively imposed by the surrounding radio reception conditions, the standardized rules and the selection parameters determined by the network operators.

In the invention, by applying a given combination of attenuations which will modify the radio reception conditions by the terminal 300 on the imposed frequency band, the terminal 300 can select a frequency band different from the imposed frequency band. The frequency bands selectable by the terminal 300 by virtue of the application of the combination of attenuations, are grouped together in a set of frequency bands included in the maximum set of frequency bands. A selected frequency band is therefore imposed by the rules and the selection parameters and possibly by a combination of attenuations when it is applied.

The set of frequency bands, that is to say the set of frequency bands selectable by the terminal 300, is not known a priori and therefore depends both on the selection and selection rules and parameters. the sequence of combinations of attenuations.

In the remainder of the description, the terms “frequency band” and “frequency band” will be used interchangeably. The term "selection of the optimum frequency band in terms of throughput or optimal throughput, from among a set of frequency bands" is understood to mean the selection of the frequency band of the set of frequency bands for which the communication has the throughput. highest amount, compared to the uplink rates on the other frequency bands of the set of frequency bands, and a downstream rate at least equal to the downstream rate on the frequency band selected by the terminal when no combination of attenuations is is applied.

The term "uplink rate" is understood to mean the quantity of data which can pass by time interval on the uplink, that is to say from the terminal to the base station, and by "downstream rate", the amount of data that can pass per time slot on the downlink, i.e. from the base station to the terminal.

[0069] [Fig. 1] Figure 1 shows a block diagram illustrating the sequence of steps of the method 100 according to the invention.

A second aspect of the invention relates to a system 500 allowing the implementation of the method 100 according to the invention. As illustrated in Figure 2, the system 500 comprises: the terminal 300; an intelligent antenna system 200.

The intelligent antenna system 200 is connected to the terminal 300 via the antenna port 301.

The term “intelligent system” is understood to mean a system possessing the electronic or computer resources necessary to process, in an autonomous manner, the data collected or received, and to be able to use the information in order to command actions.

As illustrated in Figure 2, the intelligent antenna system 200 comprises: an antenna 202; an attenuation module 201; a system board 203.

The attenuation module 201 is configured to apply a sequence of combinations of attenuations to the antenna 202.

The sequence of attenuation combinations includes a plurality of attenuation combinations.

A combination of attenuations includes at least one attenuation of the gain of the antenna 202 over a frequency band of the maximum set of frequency bands.

In the case where the invention is applied in a 4G network, a combination of attenuations comprises, for example, an attenuation on the frequency band B3 and an attenuation on the frequency band B1.

[0079] [Fig. 3] Figure 3 is a schematic representation of a first embodiment of the antenna 202 of the intelligent antenna system 200 according to the invention.

According to the first embodiment, the antenna 202 comprises: an antenna element 2021 with a broadband spiral; a cavity 2022 comprising the antenna element 2021; a power supply configured to power the antenna element 2021, comprising for example an infinite balun 2025, in FIG. 3, the infinite balun 2025 is integrated into the antenna element 2021; a 2023 coaxial cable equipped with a coaxial connector, configured to connect the 2021 antenna element to the power supply.

[0081] Cavity 2022 has a through hole 2024 and coaxial cable 2023 is configured to pass through hole 3014 such that the power supply can be connected to coaxial cable 2023 via its coaxial connector from outside of cavity 2022.

According to a second embodiment not shown in the figures, the antenna 202 comprises a broadband antenna element, for example a winding antenna or a Vivaldi antenna, and a power supply configured to supply the antenna element.

As illustrated in Figure 2, the attenuation module 201 comprises: a programmable attenuator 2010 configured to apply a sequence of attenuation combinations to the antenna 202; a 2013 controller configured to program attenuator 2010, that is, to force attenuator 2010 in the sequence of attenuation combinations to be applied to antenna 202.

[0084] [Fig. 4] Figure 4 is a schematic representation of a first embodiment of the attenuator 2010 of the intelligent antenna system 200 according to the invention.

According to the first embodiment, the attenuator 2011 comprises at least one stranded notch filter, otherwise called "spur-line" in English.

In Figure 4, the attenuator 2011 comprises four stranded notch filters 2011 -1, 2011 -2, 2011 -3, 2011 -4 in series. Each stranded notch filter 2011-1, 2011-2, 2011-3, 2011-4 comprises at least one PIN diode (for “Positive Intrinsic Negative diode”) acting as a switch.

In Figure 4, each stranded notch filter 2011 -1, 2011 -2, 2011 -3, 2011-4 comprises three PIN diodes 2012-1, 2012-2, 2012-3, uniquely identified on the first stranded notch filter 2011 -1.

In this first embodiment, the controller 2013 is configured to activate or deactivate the PIN diode (s) 2012-1, 2012-2, 2012-3 of each stranded notch filter 2011-1, 2011-2 , 2011-3, 2011-4 to increase or decrease the electrical length of the strand of the notch filter 2011 -1, 2011 -2, 2011 -3, 2011 -4. The smaller the strand size, the greater the attenuation frequency by the 2011 -1, 2011 -2, 2011 -3, 2011 -4 strand notch filter. For a notch filter with strand 2011 -1, 2011 -2, 2011 -3, 2011 -4 given having three PIN diodes 2012-1, 2012-2, 2012-3, in the case where the assembly maximum frequency bands comprises a first, a second and a third frequency bands, the controller 2013 can for example attenuate on the first frequency band by activating the three PIN diodes 2012-1, 2012-2, 2012- 3, attenuate on the second frequency band by activating two of the three diodes

PIN 2012-1, 2012-2, 2012-3 and attenuate on the third frequency band by activating one of the three PIN diodes 2012-1, 2012-2, 2012-3.

A preferred embodiment of the attenuator 2011 according to the first embodiment is illustrated in Figure 4.

The attenuator 2011 according to the preferred embodiment has an area approximately two times smaller than the area of the antenna 202 necessary to obtain a positive gain greater than 4 dB and the lowest possible volume for the antenna system. 200. The volume of the intelligent antenna system 202 is for example included in a parallelepiped with a volume of 10 cm x 10 cm x 2.5 cm.

The attenuator 2011 according to the preferred embodiment can thus attenuate only on three different high frequency frequency bands, and to obtain a sufficient attenuation level for a given frequency band, that is to say at least 15 dB, attenuator 2011 can attenuate only on two different frequency bands simultaneously at most.

According to a second embodiment not shown in the figures, the attenuator 2011 comprises for each frequency band of the set of frequency bands, a notch filter corresponding to the frequency band. The notch filters of the 2011 attenuator are mounted in parallel. The notch filter is for example a comb filter, otherwise called "hairpin filter" in English.

The system board 203 is configured to drive the 2013 controller by sending it programming instructions.

The system card 203 is also configured to carry out measurements of upward and downward flow rates via the terminal 300 connected to the intelligent antenna system 200, that is to say by connecting to the Internet via the means of sharing of connection of terminal 300.

The system card 203 is for example an SoM system card (for “System On Module”). A first step 101 of the method 100 consists, for the terminal 300, in applying the rules and the parameters received to select an initial frequency band from among the maximum set of frequency bands.

In the case where the invention is applied in a 4G network, the initial frequency band is for example B7.

A second step 102 of the method 100 consists for the system card 203, in measuring an initial upward flow and an initial downward flow on the initial frequency band, via the terminal 300.

The initial uplink rate and the initial downlink rate can each be measured after a predefined time interval.

The predefined time interval is for example a few seconds. A third step 103 of the method 100 consists in choosing the initial uplink bitrate as the reference uplink bitrate and the initial downlink bitrate as the reference downlink bitrate. A fourth step 104 of the method 100 consists, for the attenuation module 201, in applying a sequence of combinations of attenuations to the antenna 202.

[0105] During the fourth step 104, the sequence of attenuation combinations can be applied a plurality of times [0106] The attenuation combinations are applied successively by the attenuation module 201.

[0107] The sequence of combinations of attenuations can depend on at least one circumstantial information associated with the method 100 according to the invention. [0108] The circumstantial information is for example the time at which the process

100 is carried out or the location of the terminal 300.

[0109] For each combination of attenuations, a fifth step 105 and a sixth step 106 of the method 100 are carried out.

The fifth step 105 of the method 100 consists for the system card 203, in measuring, via the terminal 300, an upward flow on the frequency band selected by the terminal 300 corresponding to the combination of attenuations applied by the module d attenuation 201. [0111] The upstream flow can be measured after a predefined time interval.

If the terminal 300 does not automatically reselect a frequency band from among the set of frequency bands after the application of the combination of attenuations, the fifth step 105 is preceded by a step of forcing a selection by the terminal 300 of a frequency band among the set of frequency bands.

The forcing step is for example carried out by deactivating and then reactivating the modem of the terminal 300. Once the forcing step has been carried out, it is possible to stop the application of the combination of attenuations.

The sixth step 106 of the method 100 consists in comparing the upward flow rate measured in the fifth step 105 with an upward flow threshold depending on the reference upward flow rate, and in choosing the measured upward flow rate as the reference upward flow rate if the flow rate measured amount is strictly greater than the amount debit threshold.

[0116] The uplink debit threshold is for example equal to the sum of the reference uplink debit and a tolerance threshold.

The tolerance threshold is for example equal to 5% of the reference amount flow.

[0118] The upstream debit threshold is for example equal to the reference upstream debit.

The sequence of attenuation combinations makes it possible to select by successive elimination the optimum frequency band in terms of throughput for the terminal 300 from among the set of frequency bands. [0120] The sequence of attenuation combinations may depend on the upward flow measured at each combination of attenuations and more particularly on the comparison between the upward flow rates of two different attenuation combinations.

For example, the sequence of combinations of attenuations comprises a first combination of attenuations for which a first upward flow is measured and a second combination of attenuations for which a second upward flow is measured. If the first measured uplink rate is greater than the second measured uplink rate, the sequence of combinations of attenuations includes a third combination of attenuations while if the first measured uplink rate is less than the second measured uplink rate, the sequence of combinations of attenuations has a fourth combination of attenuations, the third combination of attenuations being different from the fourth combination of attenuations. According to a first embodiment, if the maximum set of frequency bands comprises N frequency bands, the sequence of combinations of attenuations comprises N combinations of attenuations and each combination of attenuations comprises N-1 attenuations applied to frequency bands of the maximum set of different frequency bands.

The first embodiment corresponds to a case where the capacities of the intelligent antenna system 200 do not limit the number of frequency bands that can be simultaneously attenuated. The first embodiment therefore cannot be implemented by the intelligent antenna system 200 having an attenuator 2011 according to the preferred embodiment.

[0124] In the case where the invention is applied in a 4G network in France and the frequency band B28 is not used, the maximum set of frequency bands comprises 4 frequency bands, B20, B3, B1, B7 .

[0125] In the first embodiment, each combination of attenuations comprises 3 attenuations applied to frequency bands of the maximum set of different frequency bands.

For example, the sequence of combinations of attenuations comprises: a first combination of attenuations comprising an attenuation on the frequency band B20, an attenuation on the frequency band B3 and an attenuation on the frequency band B1, this which forces the terminal 300 to select the frequency band B7; a second combination of attenuations comprising an attenuation on the frequency band B3, an attenuation on the frequency band B1 and an attenuation on the frequency band B7, which forces the terminal 300 to select the frequency band B20; a third combination of attenuations comprising an attenuation on the frequency band B20, an attenuation on the frequency band B1 and an attenuation on the frequency band B7, which forces the terminal 300 to select the frequency band B3; a fourth combination of attenuations comprising an attenuation on the frequency band B20, an attenuation on the frequency band B3 and an attenuation on the frequency band B7, which forces the terminal 300 to select the frequency band B1. According to a second embodiment, each combination of attenuations comprises at most two attenuations applied to frequency bands of the maximum set of different frequency bands.

The second embodiment corresponds to a case where the capacities of the intelligent antenna system 200 limit the number of frequency bands that can be simultaneously attenuated to two. The second embodiment can therefore be implemented by the intelligent antenna system 200 having an attenuator 2011 according to the preferred embodiment.

[0129] [Fig. 5] FIG. 5 is a schematic representation of an example of a sequence 1050 of combinations of attenuations for the second embodiment of the method 100 according to the invention.

[0130] In the case where the invention is applied in a 4G network in France and the frequency band B28 is not used, the maximum set of frequency bands comprises 4 frequency bands, B20, B3, B1, B7 .

[0131] In order to be able to be implemented by the attenuator 2011 according to the preferred embodiment, the sequence of combinations of attenuations can only include attenuations on the high-frequency frequency bands B3, B1 and B7.

As illustrated in FIG. 5, the sequence 1050 of combinations of attenuations may comprise: a first combination of attenuations 1051_1 comprising an attenuation of the frequency band of B1 and an attenuation of the frequency band of B7. Once this first combination of attenuations 1051_1 has been applied, the terminal 300 more likely selects an unattenuated frequency band, namely the frequency band B20 or the frequency band B3; a second combination of attenuations 1051_2 comprising an attenuation of the frequency band of B1 and an attenuation of the frequency band of B3. Once this first combination of 1051 _1 attenuations is applied, the terminal 300 more likely selects a unattenuated frequency band, namely the frequency band B20 or the frequency band B7; a third combination of attenuations 1051_3 comprising an attenuation of the frequency band of B3 and an attenuation of the frequency band of B7. Once this first combination of attenuations

1051 _1 applied, the terminal 300 more likely selects an unattenuated frequency band, namely the frequency band B20 or the frequency band B1.

[0133] Since the frequency band B20 is low frequency, it is less likely to be selected than a high frequency frequency band. Indeed, two reasons can explain it.

A first reason is that the antenna 202 used does not amplify the low frequency frequency bands corresponding to a negative gain, unlike the high frequency frequency bands corresponding to a positive gain, and in particular to a higher positive gain. at 6 dB.

A second reason is that the parameterization of the operators for the selection process generally favors the selection of the high frequency frequency bands because the low frequency frequency bands have the most coverage and the lowest in terms of bandwidth, and are therefore reserved in priority for terminals which do not have access to other frequencies.

Thus, once the first combination of attenuations 1051 _1 has been applied, the terminal 300 more probably still selects the frequency band B3, once the second combination of attenuations 1051 _2 has been applied, the terminal 300 more probably still selects the frequency band. frequency band B7 and once the third combination of attenuations 1051_3 has been applied, terminal 300 more likely selects frequency band B1.

Returning to the example of the first embodiment, the fifth step 105 is carried out for the first combination of attenuations, which makes it possible to obtain a first upward flow which can be associated with the frequency band B7. , then the fifth step 105 is carried out for the second combination of attenuations, which makes it possible to obtain a second upward flow that can be associated with the frequency band B20, then the fifth step 105 is carried out for the third combination of attenuations, which makes it possible to obtain a third upward flow that can be associated with the frequency band B3, and finally the fifth step 105 is performed for the fourth combination of attenuations, which makes it possible to obtain a fourth upward flow that can be associated with the band of frequencies B1.

If we consider the case where the terminal 300 had selected the frequency band B7 as the initial frequency band, which is not known a priori, and that the frequency band B1 is the frequency band of optimum upward flow rate which one seeks to determine by the method 100, during the sixth step 106 carried out for the first combination of attenuations, the first upward flow rate is equal to the reference upward flow rate itself equal to the initial upward flow rate . The reference amount debit is therefore not changed. If the second uplink debit and the third uplink debit are less than the initial uplink debit, the reference uplink debit is not modified either during the sixth step 106 carried out for the second combination of attenuations and during the sixth step 106 performed for the third combination of attenuations. During the sixth step 106 carried out for the fourth combination of attenuations, the fourth uplink rate is strictly greater than the uplink rate threshold equal here to the reference uplink rate. The reference uplink debit is therefore updated with the value of the fourth uplink debit. [0139] Since all of the attenuation combinations of the plurality of attenuation combinations have been applied, the final value of the reference uplink rate is the value of the fourth uplink rate corresponding to the fourth combination of attenuations.

The method 100 according to the invention may further include a seventh step 107 for identifying the optimum frequency band in terms of throughput. In the example of the first embodiment, the optimum frequency band in terms of bit rate can be directly identified since each combination of attenuations forces the terminal 300 to select a given frequency band. Thus, the optimum frequency band in terms of bit rate is the frequency band associated with the fourth upstream bit rate, namely the frequency band B1. In the second embodiment, the optimum frequency band in terms of throughput cannot be directly identified since a given combination of attenuations does not force the terminal 300 to select a given frequency band. The seventh step 107 then comprises, for each combination of attenuations, at least one step of comparing the upward flow rate measured for the combination of attenuations and another upward flow rate measured for another combination of attenuations of the sequence of combinations of attenuations or in the absence of application of a combination of attenuations.

[0143] [Fig. 6] FIG. 6 is a block diagram illustrating the seventh step 107 of the method 100 associated with the sequence of combinations of attenuations illustrated in FIG. 5.

At the start of the seventh step 107, a flow measurement counter D, a loop counter O, a counter Ca associated with the frequency band B3, a counter Gz associated with the frequency band B7, a counter Ci associated with the frequency band B1, a counter C20 associated with the frequency band B20 are initialized to zero.

[0145] An upstream flow DO is then measured, when no combination of attenuations is applied. The first measured upward flow DO can be the initial upward flow measured in the second step 102.

[0146] The first combination of 1051_1 attenuations is then applied and a first upstream flow D1 is measured.

The first upward flow D1 is then compared to the upward flow DO:

If the first upward flow D1 is greater than the upward flow DO, the counter C3 is incremented by 1 then is compared to a threshold A3 associated with the frequency band B3: o If the counter C3 is equal to the counter A3, the frequency band optimal in terms of throughput is the frequency band B3; o If counter C3 is lower than counter A3, counter O is compared to a loop threshold B: • If the counter O is equal to the threshold B, the optimum frequency band in terms of throughput is the frequency band Bi associated with the counter Ci of the highest value;

• If the O counter is less than the B threshold, the O counter is incremented by 1, the D counter is reset to zero, a new measurement of the upstream flow DO is performed and the first combination of attenuations 1051 _1 is applied again.

If the first upward flow D1 is equal to the upward flow DO, the counter D is incremented by 1, the counter C3 is incremented by ½ and the second combination of attenuations 1051 _2 is applied;

If the first upward flow D1 is less than the upward flow DO, the second combination of attenuations 1051_2 is applied.

[0148] The second combination of 1051_2 attenuations is then applied and a second upstream flow D2 is measured.

The second upward flow D2 is then compared to the first upward flow D1:

If the second upward flow D2 is greater than the first upward flow D1, the counter C7 is incremented by 1 then is compared to a threshold kl associated with the frequency band B7: o If the counter C7 is equal to the counter kl, the band of Optimal frequencies in terms of throughput is the frequency band B7; If the counter Cl is lower than the counter kl, the counter O is compared to a loop threshold B:

• If the counter O is equal to the threshold B, the optimum frequency band in terms of throughput is the frequency band Bi associated with the counter Ci of the highest value;

• If the O counter is less than the B threshold, the O counter is incremented by 1, the D counter is reset to zero, a new measurement of the rising flow D0 is carried out and the first combination of attenuations 1051 _1 is applied again. If the second upward flow D2 is equal to the first upward flow D1, the counter D is incremented by 1, the counter C7 is incremented by ½ and the third combination of attenuations 1051 _3 is applied;

If the first upward flow D1 is less than the upward flow DO, the third combination of attenuations 1051 3 is applied.

[0150] The third combination of 1051_3 attenuations is then applied and a third upstream flow D3 is measured.

The third upward flow D3 is then compared to the second upward flow D2:

If the third upward flow D3 is greater than the second upward flow D2, the counter C1 is incremented by 1 then is compared to a threshold A1 associated with the frequency band B1: o If the counter C1 is equal to the counter A1, the band of Optimal frequencies in terms of throughput is the frequency band B1; o If counter C1 is lower than counter A1, counter O is compared to a loop threshold B:

• If the O counter is less than the B threshold, the O counter is incremented by 1, the D counter is reset to zero, a new measurement of the upward flow D0 is carried out and the first combination of attenuations 1051 _1 is applied again.

If the third upward flow D3 is equal to the second upward flow D2, the counter D is incremented by 1, the counter C1 is incremented by ½ and the counter D is compared to the value 3: o If the counter D is equal to 3, the counter C20 is incremented by 1. The counter C20 is then compared with a threshold A20 associated with the frequency band B20: o If the counter C20 is equal to the counter A20, the optimum frequency band in terms of throughput is the frequency band B20; o If counter C20 is lower than counter A20, counter O is compared to a loop threshold B:

The seventh step 107 is therefore interrupted when the probability associated with a given frequency band Bi, represented by the counter Ci, is sufficient, that is to say equal to the threshold Ai, or when the sequence of combinations d The attenuations have been applied enough times, that is, loop counter O equals loop threshold B.

[0153] The thresholds Ai and B depend, for example, on the circumstantial information. [0154] The thresholds Ai and B can have a reduced value, for example a value 2 and a value 4 respectively, if the band of frequencies of optimal flow is already known for the same time and the same seasonal period following previous measurements. stable.

[0155] The thresholds Ai and B may have a greater value, for example a value 5 and a value 7 respectively, during periods of seasonal transitions for example or when a new intelligent antenna system is brought into service. In general, the thresholds Ai and B have for example respectively a value of 4 and a value of 5.

The method 100 can then further include an eighth step 108 consisting in storing the optimum frequency band in terms of throughput identified in the seventh step 107 in a database. In the database, the optimum frequency band in terms of throughput is for example associated with the circumstantial information corresponding to the method 100.

For example, if the circumstantial information is the time at which the method 100 is carried out and the method 100 is carried out at 5.30 p.m., taking the previous example of the first embodiment in which the optimum frequency band in terms of throughput is the frequency band B1, the frequency band B1 is associated with 5.30 p.m. in the database.

The database stores, for example, the optimum frequency band in terms of throughput for each implementation of the method 100.

For a given embodiment of the method 100, the sequence of combinations of attenuations may depend on the optimum frequency band (s) in terms of throughput corresponding to the circumstantial information associated with the method 100 in the database.

Returning to the previous example if the method 100 is associated with the circumstantial information 5.30 p.m., as the database comprises the frequency band B1 associated with 5.30 p.m., the sequence of combinations of attenuations can for example be chosen for test frequency band B1 first. [0163] Thus, taking the example of the second embodiment again, the third combination of attenuations 1051_3 for which the frequency band B1 has the most chance of being selected by the terminal 300, can be placed first in the sequence of combinations of attenuations.

The threshold Ai associated with the frequency band B1 can also be reduced with respect to the other thresholds Ai.

[0165] A ninth step 109 of the method 100 then consists in applying to the antenna 202 by means of the attenuation module 201, the combination of attenuations corresponding to the reference uplink rate. [0166] In the example of the first embodiment, the ninth step 109 consists of applying the fourth combination of attenuations to the antenna 202.

The ninth step 109 is only carried out in the case where the reference uplink debit is greater than the initial uplink debit, since if the debit initial uplink is the optimal uplink rate, the terminal 300 selects the optimal uplink rate frequency band without needing to apply any combinations of attenuations to the antenna system 301 of the terminal 300.

If the terminal 300 does not automatically reselect a frequency band from among the set of frequency bands after the application of the combination of attenuations corresponding to the reference uplink rate, the ninth step 109 is preceded by a forcing step a selection by the terminal 300 of a frequency band from among the set of frequency bands. [0169] Once the forcing step has been carried out, it is possible to stop the application of the combination of attenuations corresponding to the reference amount flow.

A tenth step 110 of the method 100 then consists in measuring a downward flow rate and in comparing it with a downward flow rate threshold depending on the reference downward flow rate.

[0171] If the measured downward flow is greater than or equal to the downward flow threshold, the combination of attenuations applied corresponds to the optimum frequency band in terms of flow.

If the measured downward flow rate is less than the downward flow threshold, we are interested in the frequency band which gave the second best upward flow, that is to say the upward flow among the upward flow rates measured at the fifth step 105 of method 100, the highest after the reference uplink rate obtained after the application of the sequence of combinations of attenuations. If this frequency band is the initial frequency band, the initial frequency band corresponds to the optimum frequency band in terms of bit rate. If this frequency band is different from the initial frequency band, the ninth step 109 and the tenth step of the method 100 are carried out for the combination of attenuations corresponding to this frequency band, and so on until the descending rate measured in the tenth step 110 is greater than or equal to the descending rate threshold.

[0173] The descending rate threshold is for example equal to the sum of the reference descending rate and a tolerance threshold.

The tolerance threshold is for example equal to 5% of the reference downward flow. The descending rate threshold is for example equal to the reference descending rate.

[0176] The method 100 is carried out as soon as a repetition condition is met. The repetition condition is for example linked to a clock. In this case, the method 100 is for example carried out periodically, every T clock ticks or at certain predetermined times.

[0178] The repetition condition is, for example, linked to a detectable change of environment, for example seasonal, in particular during school holidays.

The repetition condition is for example linked to a significant flow variation compared to an expected flow. The expected flow rate is for example equal to an average flow rate obtained during a first implementation of the method 100 carried out when the terminal 300 is switched on, called the calibration phase.

Claims

[Claim 1] A method (100) for automatically selecting by a terminal (300) an optimum frequency band in terms of throughput from among a set of frequency bands selected by the terminal (300) to establish a communication with a base station (400), the set of frequency bands belonging to a maximum set of known frequency bands, characterized in that the terminal (300) is connected to an external intelligent antenna system (200) comprising at least one antenna (202), a attenuation module (201) and a system board (203) and in that the method (100) comprises, after reception by the terminal (300) of at least one message from the base station (400) comprising a plurality rules and parameters to be applied by the terminal (300) to select a frequency band from among the set of frequency bands, the following steps:

- Selection by the terminal (300) of an initial frequency band from among the set of frequency bands by applying the plurality of rules and parameters (101);

- Measurement of an initial upward flow and an initial downward flow by the system board (203) via the terminal (300) on the initial frequency band (102);

- Choice of the initial uplink rate as the reference uplink rate and of the initial downlink rate as the reference downlink rate (103);

- Application by the attenuation module (201) of at least one sequence (1050) of combinations of attenuations (1051 _1, 1051 _2, 1051 _3) to the antenna (202), each combination of attenuations ( 1051 _1, 1051 _2, 1051_3) comprising at least one attenuation of the gain of the antenna (202) on a given frequency band of the maximum set of frequency bands (104): o For each combination of attenuations (1051_1, 1051 _2, 1051 _3) applied, measurement of an upward flow (D1, D2, D3) by the system board (203) via the terminal (300, 105):

• If the measured upward flow (D1, D2, D3) is strictly greater than an upward flow threshold depending on the flow reference amount, choice of the measured amount flow (D1, D2, D3) as the reference amount flow (106);

- If the reference uplink rate is greater than the initial uplink rate, application to the antenna (202) of the combination of attenuations (1051 _1, 1051 _2, 1051 _3) corresponding to the reference uplink rate by the module of attenuation (201, 109): o Measurement of a downstream flow by the system board (203) via the terminal (300, 110):

• If the measured downward flow is greater than or equal to a downward flow threshold depending on the reference downward flow, the combination of attenuations (1051 _1, 1051 _2, 1051 _3) applied corresponds to the optimum frequency band in terms of flow.

[Claim 2] A method (100) according to claim 1, characterized in that, if the maximum set of frequency bands comprises N frequency bands, the sequence (1050) of combinations of attenuations (1051 _1, 1051 _2, 1051 _3 ) comprises N combinations of attenuations (1051 _1, 1051 _2, 1051 _3), each combination of attenuations (1051 _1, 1051 _2, 1051_3) comprising N-1 attenuations applied on frequency bands of the maximum set of frequency bands different.

[Claim 3] A method (100) according to claim 1, characterized in that each combination of attenuations (1051_1, 1051 _2, 1051 _3) comprises at most two attenuations applied to frequency bands of the maximum set of different frequency bands .

[Claim 4] A method (100) according to any one of the preceding claims, characterized in that it further comprises a step (107) of identifying the optimum frequency band in terms of throughput.

[Claim 5] A method (100) according to any one of the preceding claims, characterized in that it is associated with at least one circumstantial item of information.

[Claim 6] A method (100) according to claims 4 and 5, characterized in that it comprises a step (108) of storing the optimum frequency band in terms of throughput identified in a database, the optimum frequency band in terms of throughput being associated with the circumstantial information in the database.

[Claim 7] A method (100) according to claim 6, characterized in that the sequence of combinations of attenuations depends on the associated circumstantial information or on the optimal frequency band (s) in terms rate corresponding to the associated circumstantial information in the database.

[Claim 8] A method (100) according to any one of the preceding claims, characterized in that, for the initial frequency band and for each combination of attenuations (1051 _1, 1051 _2, 1051 _3) applied, the upward flow and / or descending (D1, D2, D3, D0) is measured after a predefined time interval.

[Claim 9] A method (100) according to any one of the preceding claims, characterized in that it is carried out as soon as a repetition condition is met, the condition depending on a clock, on a change of environment. detectable or a significant flow variation compared to an expected flow.

[Claim 10] A method (100) according to any one of the preceding claims, characterized in that it comprises a step of forcing a selection by the terminal (300) of a frequency band from among the set of bands. frequency, after each application of a combination of attenuations (1051 _1, 1051 _2, 1051_3).

[Claim 11] System (500) for implementing the method (100) according to any one of the preceding claims, characterized in that it comprises: - a terminal (300) comprising at least one antenna port (301) configured to allow a connection between an intelligent antenna system (200) and the terminal (300);

- an intelligent antenna system (200) comprising: an antenna (202); o an attenuation module (201) comprising:

• a programmable attenuator (2010) configured to apply to the antenna (202) a sequence (1050) of combinations of attenuations (1051 _1, 1051 _2, 1051 _3), each combination of attenuations (1051 _1, 1051_2, 1051 _3) comprising at least one attenuation of the gain of the antenna (202) on a given frequency band;

• a controller (2013) configured to program the attenuator (2010); o a system board (203) configured to drive the controller (2013) and perform uplink and downlink flow measurements via the terminal (300) when the system (200) is connected to the terminal (300) via the antenna port (301) .

[Claim 12] System (500) according to claim 11, characterized in that the attenuator (2011) comprises at least one stranded notch filter (2011 -1, 2011 -2, 2011 -3, 2011 -4) , and at least one PIN diode (2012-1, 2012-2, 2012-3), the controller (2013) being configured to activate or deactivate the PIN diode (2012-1, 2012-2, 2012-3) to increase or decrease the electrical length of the strand notch filter strand (2011 -1, 2011 -2, 2011 -3, 2011 -4).

[Claim 13] A system (500) according to claim 12, characterized in that the attenuator (2010) comprises a plurality of stranded notch filters (2011 -1, 2011 -2, 2011 -3, 2011 -4) serial.

[Claim 14] System (500) according to any one of claims 11 to 13, characterized in that the antenna (202) comprises:

- a broadband spiral antenna element (2021);

- a power supply configured to power the antenna element (2021) via a coaxial cable (2023);

- a cavity (2022) comprising the antenna element (2021) and a through hole (2024); the coaxial cable (2023) being configured to pass through the hole (2024) so that the power supply is outside the cavity (2022). [Claim 15] A system (500) according to claim 14, characterized in that the re-supply comprises an infinite balun (2025).